Quantitative trait loci for cell wall components in recombinant inbred lines of maize (Zea mays L.) II: leaf sheath tissue

While maize silage is a significant feed component in animal production operations, little information is available on the genetic bases of fiber and lignin concentrations in maize, which are negatively correlated with digestibility. Fiber is composed largely of cellulose, hemicellulose and lignin, which are the primary components of plant cell walls. Variability for these traits in maize germplasm has been reported, but the sources of the variation and the relationships between these traits in different tissues are not well understood. In this study, 191 recombinant inbred lines of B73 (low-intermediate levels of cell wall components, CWCs) × De811 (high levels of CWCs) were analyzed for quantitative trait loci (QTL) associated with CWCs in the leaf sheath. Samples were harvested from plots at two locations in 1998 and one in 1999 and assayed for neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL). QTL were detected on all ten chromosomes, most in tissue specific clusters in concordance with the high genotypic correlations for CWCs within the same tissue. Adjustment of NDF for its subfraction, ADF, revealed that most of the genetic variation in NDF was probably due to variation in ADF. The low to moderate genotypic correlations for the same CWC across leaf sheath and stalk tissues indicate that some genes for CWCs may only be expressed in certain tissues. Many of the QTL herein were detected in other populations, and some are linked to candidate genes for cell wall carbohydrate biosynthesis.     

Genetic mapping and analysis of quantitative trait loci affecting fiber and lignin content in maize

Plant cell walls of forage provide a major source of energy for ruminant animals. Digestion of cell walls is limited by the presence of lignin, therefore the improving the digestibility of forages by reducing lignin content is a major goal in forage crop breeding programs. A recombinant inbred line maize population was used to map quantitative trait loci (QTL) for neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) of leaf-sheath and stalk tissues. All traits were positively genetically correlated. The larger genetic correlations were between NDF and ADF in sheaths (r = 0.84), NDF and ADF (r = 0.96), ADF and ADL (r = 0.83), and NDF and ADL (r = 0.76) in stalks. Twelve QTL were detected for NDF and 11 QTL for ADF in leaf-sheaths. Eight QTL detected for both traits were defined by the same or linked marker loci. Eight QTL were associated with leaf-sheath ADL. Eleven QTL were detected for NDF and ADF, and 12 QTL for ADL in stalks. Nine of eleven QTL detected for both NDF and ADF in stalks coincided in their genomic position. A high proportion of QTL detected for these traits had the same parental effects and genomic locations, suggesting that it is only necessary to select on one fiber component (NDF or ADF) to improve digestibility. Favorable correlated responses of unselected fiber components are expected due to coincident genomic locations of QTL and the high genetic correlation between fiber components. Several QTL detected in this study coincided in their positions with putative cellulose synthase genes from maize.     

QTL analyses of fiber components and crude protein in an annual × perennial ryegrass interspecific hybrid population

Annual (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrasses are two important forage and turfgrass species. Improving the digestibility of forage by decreasing fiber content is a major goal in forage crop breeding programs. An annual × perennial ryegrass interspecific hybrid population was used to map quantitative trait loci (QTLs) for fiber components, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL), and crude protein (CP). Samples were harvested three times in August and September 2003 and August 2004, respectively. Simple interval mapping was used to detect QTLs from both the male and female parental maps previously developed for the population. Fiber components were all correlated positively with each other and were negatively correlated with CP. The largest correlations were between NDF and ADF with r = 0.86, 0.72, and 0.82 for each of the three harvests. All four traits showed intermediate broad-sense heritability values ranging from 0.35 to 0.72. A total of 63 QTLs were detected for the four traits measured over the three harvests from both the female and male maps. Coincident QTLs were detected on linkage groups (LGs) 2, 6, and 7 for NDF, LGs 1, 2, and 7 for ADF, LGs 6 and 7 for ADL, and LG 2 for CP, respectively. Coincident QTLs were also detected on LGs 2, 6, and 7 for NDF and ADF, providing evidence of the genetic basis of the observed high level of phenotypic correlation. The QTLs on LGs 2, 6, and possibly 7 for fiber components were co-located on the same LG as several lignin biosynthetic genes from perennial ryegrass.     

Genetic relationships between resistance to stalk-tunneling by the European corn borer and cell-wall components in maize population B73×B52

The objective of this study was to assess the relationships among quantitative trait loci (QTL) detected for European corn borer (ECB) tunneling and cell-wall components (CWC) neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) content in leaf-sheath and stalk tissues in a maize recombinant inbred line population derived from inbred lines B73 and B52. Most of the QTL for ECB resistance (10/13) were at QTL positions for one or more CWC. Of the 12 QTL for NDF and ADF in leaf-sheaths, five for each trait were at or near QTL for ECB tunneling. Four of these five QTL for NDF and ADF mapped to common locations. Four of the eight leaf-sheath ADL QTL were detected in the same genomic regions as ECB QTL. For stalk tissue, four regions contained common/overlapping QTL for ECB tunneling, NDF, and ADF. Six such regions were observed for stalk ADL and ECB tunneling. Seven of the ten QTL associated with both CWC and ECB tunneling contributed to the negative correlations observed between these traits, while relatively few QTL effects were positively correlated. This suggests that while CWC contribute to ECB resistance in this population, other mechanisms and other genes also are involved. Several QTL contributing to the negative correlations between ECB tunneling and CWC in the leaf-sheaths mapped to similar positions as QTL detected in tropical maize populations for resistance to leaf-feeding by Diatraea grandiosella Dyar and Diatraea saccharalis Fabricus. These regions may contain genes involved in the synthesis of cellulose, hemicellulose, and lignin in the leaf-blades and leaf-sheaths of maize.     

Comparative mapping of fiber,protein, and mineral content QTLs in two interspecific <Emphasis Type="Italic">Leymus</Emphasis> wildrye full-sib families

Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and mineral content are important components of forage quality in grasses. Elevated [K]/([Ca] + [Mg]) ratios (KRAT) substantially increase the risk of grass tetany (hypomagnesemia) in grazing animals, which is a serious problem associated with some cool-season grasses. The objectives of this study were to map and compare QTLs controlling concentrations of CP, NDF, ADF, Al, B, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, S, Si, Zn, and KRAT in two full-sib Leymus triticoides × (L. triticoides × L. cinereus) TTC1 and TTC2 families. Significant genetic variation and QTLs were detected for all traits, with evidence of conserved QTLs for ADF (LG1a, LG5Xm, LG7a), NDF (LG7a), Ca (LG1b), CP, (LG5Xm), KRAT (LG3b, LG6b, LG7a, LG7b), Mn (LG2b, LG3b, LG4Xm), and S (LG3a) content in both TTC1 and TTC2 families. Moreover, the direction of QTL effects was the same for 13 of the 14 homologous QTLs in both families. The TTC1 and TTC2 KRAT QTLs on LG7a and LG7b were located near markers defining homoeologous relationships between the sub-genomes of allotetraploid Leymus, suggesting possible QTL homoeology. Another 88 QTLs were unique to one family or the other, but many of these clustered in genome regions common between the two families. These results will support development of new Leymus wildrye forages and help characterize genes controlling mineral uptake and fiber synthesis.     

Ensiling characteristics, nutrient composition, and in situ ruminal and whole tract degradability of brown midrib and leafy corn silage

A study was conducted to compare the ensiling characteristics, chemical composition, and the ruminal and total tract nutrient degradabilities of leafy (Cargill F227) and brown midrib (Mycogen TMF94) corn silage hybrids. Corn was grown in Saint-Jean-sur-Richelieu, Quebec, Canada, harvested at a target 350 g kg(-1) dry matter (DM) content, and ensiled in mini-silos for 0, 2, 4, 8, 16, and 45 d. Two non-lactating Holstein cows fitted with ruminal and proximal duodenal cannulae were used to determine ruminal and whole tract nutrient degradability. Forage from both hybrids went through a rapid fermentation with a sharp decline in pH during the first 2 d of ensiling, pH in both silage being less than 4.0 after 45 d. Lactic acid concentration was however greater for leafy than brown midrib corn. Chemical analysis of silage after 45 d of ensiling revealed that hybrids differed in their composition. Compared to leafy corn, brown midrib corn had lower neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), crude protein (CP), and neutral detergent and acid detergent insoluble proteins, but higher starch and net energy of lactation (NEL) values. Results of the in situ incubation experiment indicated that compared to leafy corn brown midrib corn had greater ruminal DM (64 vs. 54%), CP (73 vs. 71%), and NDF (32 vs. 24%) degradabilities. Brown midrib corn silage also had greater DM ruminal (53 vs. 48%) and total tract (67 vs. 61%) digestibilities, as well as greater NDF ruminal (34 vs. 25%), intestinal (10 vs. 8%), and total tract (43 vs. 33%) digestibilities. Type of corn hybrid will thus greatly affect silage chemical composition and nutrient digestibility.     

Nutritional content of savanna plant foods: implications for browser/grazer models of ungulate diversification

Models of herbivore diversification rely heavily on adaptations that reflect the nutritional quality of foods consumed. In particular, browsers and grazers are expected to show dichotomous adaptations to deal with high quality (concentrate) browse-based and poor quality grass-based diets, respectively. In this study, we test the widespread assumption that browse represents a higher quality food source than grass. We analyzed plants from a South African savanna, collected over one dry and one wet season across several habitat types, for percent nitrogen (%N), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) to compare variations in nutritional value of different food types. Results show consistently higher %N and lower NDF and ADF of tree foliage and forbs compared to monocots, but the former have consistently higher ADL, implying a higher fiber digestibility in grass compared with browse. Some fruit species have a high NDF and ADL content, implying poorer nutritional value than is commonly assumed. Our findings are in agreement with several other studies depicting relatively poor digestibility of browse (tree foliage and fruit) compared to grass. Reference to browse as high quality foods is therefore misleading, and models of herbivory that rest on this assumption require revision. The more efficient fiber digestibility recorded in grazers compared to browsers cannot be treated as an adaptation to poor quality diets, but rather to maximize benefits of higher fiber digestibility of grass. Spatio-seasonal variations in plant nutritional seem to reflect seasonal and spatial diet changes expected for grazers and intermediate (mixed) feeders. We propose that future studies require further detail on variations in diet, diet quality, and digestive efficiency to properly understand mechanisms of adaptation.     

玉米自交系秸秆品质性状鉴定与评价

利用近红外漫反射光谱法,对50份常用普通玉米自交系和50份高油自交系秸秆的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、可溶性糖(WSC)和粗蛋白(CP)4个品质性状进行了鉴定评价和相关性分析。结果表明,各品质性状变异较大,各性状自交系间差异均达极显著水平。不同品质性状变异程度不同,其中WSC含量变异最大,变异系数达34.23%。WSC与NDF、ADF极显著负相关,NDF与ADF含量极显著正相关。高油系表现为高WSC、CP和低NDF、ADF含量,总体上高油系秸秆品质优于普通玉米。     

Effects of groundnut stover or Bermudagrass hay supplementation to doe kids on winter hardwood range

Goats in north-central Texas raised on rangeland often face winter forage quantity and quality deficits that may be mitigated by feeding hay or stover. Groundnut (Arachis hypogea) stover (8% CP, 35% ADF, 43% NDF and 8% acid detergent lignin (ADL) DM basis) and bermudagrass (Cynodon dactylon) hay (12% CP, 33% ADF, 73% NDF, and 5% ADL DM basis) were tested at Stephenville, Texas as 0.0, 0.5, or 2.0% BW supplement/substitution diets on 18 kg Boer X Spanish doe kids browsing native hardwoods (8 ha⁻¹). Both hay and stover were fed ad libitum in a traditional feedlot, using a complete formulated feed ration as a control. Trials ran for 10 weeks from January to March in 2003 (134 mm rainfall) and in 2004 (182 mm rainfall). Goats receiving 0.5% and 2% BW bermudagrass or 2% BW groundnut stover had greater ADG than those in the control and 0.5% BW groundnut paddocks (P < 0.05). Goats fed complete ration in the drylot had greater (P < 0.05) ADG than those eating either hay or stover ad libitum. Bermudagrass hay rejected by goats in the hardwood trial was 20% lower in CP, 7% greater in NDF, 8% greater in ADF, and 9% greater in ADL than the original fed hay; groundnut stover refusals were 21% lower in CP, 12% greater in NDF, 19% greater in ADF, and 20% greater in ADL concentration than the stover when fed. Supplementing goats on hardwood range with bermudagrass hay or groundnut stover may improve ADG when browse is scarce or of poor quality.     

Digestibility of a high-fiber biscuit-based diet by black and white colobus (Colobus guereza)

The acceptability and digestibility of a high-fiber biscuit-based diet was investigated using two adult male Colobus guereza animals. Although the animals were initially reluctant to accept the biscuit, it was eventually readily consumed. Apparent digestion coefficients for the diet (average composition, dry matter basis: 16% crude protein, 25% neutral detergent fiber (NDF), 9.5% acid detergent fiber (ADF), 1.2% acid lignin) determined by total fecal collection were 0.871 for dry matter, 0.813 for NDF, 0.693 for ADF, and 0.208 for acid lignin. Fiber digestive capabilities in C. guereza generally exceeded those reported in ruminant species based on predictive equations. Use of acid lignin and Cr₂O₃ as markers underestimated dry matter digestibility by 3.9 and 6.0%, respectively.     

Expression of fungal cellulase gene in <Emphasis Type="Italic">Lactococcus lactis</Emphasis> to construct novel recombinant silage inoculants

The facultative anaerobic bacterium Lactococcus lactis has been used as a host for expression of a gene isolated from the anaerobic rumen fungus Neocallimastix sp. The coding region of the cellulase gene was obtained from the fungus with the aid of polymerase chain reaction amplification. The gene was then transformed into pCT vector system and the constructed recombinant plasmid was introduced into two L. lactis strains (IL403 and MG1363) by electroporation. The gene encoding the fungal originated cellulase was expressed in both strains successfully although the expression level was relatively lower in comparison with the original enzyme activity. Genetically modified L. lactis strains were used as silage inoculants for pre-biodegradation of the plant biomass during ensiling. That treatment resulted in a notable reduction of the acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents of the plant biomass used as silage material. Inoculation with recombinant strain IL1043 resulted in 4.8 and 9.7 % decrease in NDF and ADF contents, respectively while the inoculation of silage with strain MG1363 decreased the ADF content by >5 %.     

Effect of ensiling sudax fodder with broiler litter and Candida yeast on the changes in different fiber fractions

Sudax fodder was ensiled in laboratory silos without or with the addition of 20, 30 or 40% broiler litter and 6% molasses, each without or with yeast inoculant (Candida utilus). Different fiber fractions were analyzed at the start of the ensiling and at 10-day intervals thereafter for 40 days. NDF, ADF, cellulose and lignin increased and cell contents decreased as a result of fermentation during ensiling. The addition of increasing levels of broiler litter not only decreased NDF, hemicellulose and cellulose, with a simultaneous increase in ADF content, but also extended the time course of fermentation during ensiling. The yeast inoculant failed to produce any significant effect on the fermentation characteristics or on any of the fiber fractions of the silage.     

Cell Wall Composition and Ruminant Digestibility of Various Maize Tissues Across Development

Maize stover, including stalks, leaves, and cobs, has potential utility as a cellulosic biofeedstock. Understanding how total stover ethanol potential is affected by the proportion and quality of major plant components would facilitate the genetic improvement of stover quality and inform decisions regarding which plant parts should be targeted for harvesting. Our objectives were to determine how the proportion and composition of plant components affected ethanol potential and whether there are early season predictors of stover quality at maturity. Twenty-three hybrids were evaluated including 20 from a factorial mating design between five silage inbred lines and four commercial inbreds and a brown-midrib3, a Leafy1, and a commercial grain hybrid checks. Plants were harvested and dissected into component parts at developmental stages vegetative 3, vegetative 12, reproductive 3, and reproductive 6 (R6). Tissues were evaluated for acid detergent fiber (ADF), neutral detergent fiber (NDF), and NDF digestibility (NDFD). Stalk was the largest fraction of whole plant dry matter (46.2%) and had the lowest NDFD (3,750 g/kg) at R6. No relationship was found between stalk ADF at early developmental stages and whole plant ADF at R6, suggesting that quality at early developmental stages is not indicative of quality at physiological maturity. Differences were observed among hybrids for ADF and NDF for most plant parts evaluated. Hybrid-by-developmental stage and hybrid-by-plant part interactions were statistically significant. This indicates that there is minimal opportunity to identify superior hybrids for biofuel production based on the proportion of total biomass represented by a plant part and its quality at early developmental stages. Maximum conversion efficiency is attained when leaves are harvested compared to other tissue types at physiological maturity.     

Erratum to: Cell Wall Composition and Ruminant Digestibility of Various Maize Tissues Across Development

Maize stover, including stalks, leaves, and cobs, has potential utility as a cellulosic biofeedstock. Understanding how total stover ethanol potential is affected by the proportion and quality of major plant components would facilitate the genetic improvement of stover quality and inform decisions regarding which plant parts should be targeted for harvesting. Our objectives were to determine how the proportion and composition of plant components affected ethanol potential and whether there are early season predictors of stover quality at maturity. Twenty-three hybrids were evaluated including 20 from a factorial mating design between five silage inbred lines and four commercial inbreds and a brown-midrib3, a Leafy1, and a commercial grain hybrid checks. Plants were harvested and dissected into component parts at developmental stages vegetative 3, vegetative 12, reproductive 3, and reproductive 6 (R6). Tissues were evaluated for acid detergent fiber (ADF), neutral detergent fiber (NDF), and NDF digestibility (NDFD). Stalk was the largest fraction of whole plant dry matter (46.2%) and had the lowest NDFD (375.0 g/kg) at R6. No relationship was found between stalk ADF at early developmental stages and whole plant ADF at R6, suggesting that quality at early developmental stages is not indicative of quality at physiological maturity. Differences were observed among hybrids for ADF and NDF for most plant parts evaluated. Hybrid-by-developmental stage and hybrid-by-plant part interactions were statistically significant. This indicates that there is minimal opportunity to identify superior hybrids for biofuel production based on the proportion of total biomass represented by a plant part and its quality at early developmental stages. Maximum conversion efficiency is attained when leaves are harvested compared to other tissue types at physiological maturity.     

QTL for fibre-related traits in grain × sweet sorghum as a tool for the enhancement of sorghum as a biomass crop

Compared to maize and temperate grasses, sorghum has received less attention in terms of improving cell wall components. The objectives of this study were to identify quantitative trait loci (QTL) with main effects, epistatic and pleiotropic effects along with QTL × environment (QE) interactions controlling fibre-related traits in sorghum. Neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, fresh leaf mass, stripped stalk mass, dry stalk mass, fresh biomass and dry biomass were analysed from a population of 188 grain × sweet sorghum recombinant inbred lines. A genetic map consisting of 157 DNA markers was constructed, and QTL were detected using composite interval mapping (CIM). CIM detected more than 5 additive QTL per trait explaining 7.1–24.7% of the phenotypic variation. Abundant co-localization of these QTL was observed across all chromosomes, and the highest cluster was identified on chromosome 6. Searching for candidate genes using the confidence interval of our QTL clusters reveals that these clusters might comprise a set of genes that are tightly linked. Some QTL showed multiple effects; however, the allele for each trait was favouring the parent with the increasing effect. QE interactions were observed for QTL showing multiple effects. Additive × additive interaction was observed for 7 out of 10 traits, indicating the importance of epistatic analysis. However, the phenotypic variation explained by digenic interactions was lower compared to the individual QTL. Our results indicate that various genetic components contribute to fibre-related traits and should be considered during the enhancement of sorghum for lignocellulosic biomass.     

In vitro studies and short-term feeding trial in lambs to evaluate plantain sheath (Musa sapientum) as a feed for ruminants

Plantain sheath (Musa sapientum) contained 6.4% dry matter and 3.4% crude protein, 31.4% crude fibre, 34.6% cellulose, 15.5% hemicellulose and 6% lignin in dry matter.

Digestibility in vitro studies with fistulated bucks revealed a dry matter disappearance of 53.3% after 24 h incubation. The digestibility of neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose after 24 h fermentation was 32.2, 21.5 and 30.3%, respectively. After 48 h fermentation, the dry matter digestibility increased to 63.4%, NDF to 47.0%, ADF to 32.2% and cellulose to 42.3%.

A 45-day feeding trial was conducted with 16 crossbred lambs. Plantain sheath replaced paragrass hay dry matter at 32.6, 54.7 and 76.6% levels. Dried plantain sheath, which contributed 14.1, 25 and 34.5% of total dry matter intake, helped a daily gain of 31.1, 28.9 and 37.8 g when fed mixed with concentrate feed.     

Exploitation of a natural pasture by wild horses: comparison between nutritive characteristics of the land and the nutrient requirements of the herds over a 2-year period

In the Molise region (Italy), some autochthonous populations are still bred and, between them, some wild horses named 'Pentro horses.' The breeding area is a natural pasture. It is 2200 ha extended including a broad plane surrounded by wooden hills. The aim of this research was to determine the nutritional characteristics of this area over a 2-year period to improve the management of the herd and to define the stocking rate in relation to the forage production in terms of production and quality. The forage samples were collected over two successive years during the grazing period (May to October) from five experimental areas and analysed for dry matter (DM), organic matter (OM), crude protein (CP), crude fibre (CF), neutral-detergent fibre (NDF), acid-detergent fibre (ADF), acid-detergent lignin (ADL) and gross energy (GE). Horse feed units (HFU) and horse-digestible crude protein (HDCP) were also predicted. Data were analysed with a one-way ANOVA test using month and area as factors. The DM, HFU and HDCP total production was determined to be compared with the total nutrient requirements of the herds from May to October. The results show that seasonal and yearly climatic variations significantly affect chemical composition and nutritive value of the pasture. The parameters most influenced were DM, CP, ADF and to a less extent NDF, while OM, ADL and GE show smaller differences during the observed period. The results show a low production per ha; nevertheless, because of the low stocking rate (0.3 to 0.6 head per ha), nutrient production meets the nutrient requirements of the horses regarding DM and energy. The differences among the areas have to be ascribed to the different botanical compositions and to the different draining capacity of the soil, and also in this case the greatest variations are for DM, CP and ADF.     

High levels of linkage disequilibrium and associations with forage quality at a Phenylalanine Ammonia-Lyase locus in European maize (Zea mays L.) inbreds

Forage quality of maize is influenced by both the content and structure of lignin in the cell wall. Phenylalanine Ammonia-Lyase (PAL) catalyzes the first step in lignin biosynthesis in plants; the deamination of L-phenylalanine to cinnamic acid. Successive enzymatic steps lead to the formation of three monolignols, constituting the complex structure of lignin. We have cloned and sequenced a PAL genomic sequence from 32 maize inbred lines currently employed in forage maize breeding programs in Europe. Low nucleotide diversity and excessive linkage disequilibrium (LD) was identified at this PAL locus, possibly reflecting selective constrains resulting from PAL being the first enzyme in the monolignol, and other, pathways. While the association analysis was affected by extended LD and population structure, several individual polymorphisms were associated with neutral detergent fiber (not considering population structure) and a single polymorphism was associated with in vitro digestibility of organic matter (considering population structure).     

Food selection in relation to nutritional chemistry of Cao Vit gibbons in Jingxi,China

The Cao Vit gibbon (Nomascus nasutus) has only one population with about 110 individuals living in a degraded karst forest along the China–Vietnam border. Investigation of food choice in relation to chemical nutrition will offer important insights into its conservation. We studied the food choice of two groups of Cao Vit gibbons using instantaneous scan sampling in Bangliang National Nature Reserve, Guangxi, China, over 4 years, and analyzed the chemical components (total nitrogen, TN; water-soluble sugar, WSS; crude fat, CF; neutral detergent fiber, NDF; acid detergent fiber, ADF; acid detergent lignin, ADL; condensed tannin, CT; and ash) of 48 food plant parts and 22 non-food plant parts. Fruits and figs that are rich in sugar are important food resources for gibbons. For other food types, flowers are a good source of total nitrogen and carbohydrates, and leaves and buds provide sources of protein and minerals. Cao Vit gibbons selected fruits that contain less total nitrogen, less acid detergent fiber and more water-soluble sugar than non-food fruits. Several food species that were heavily consumed by Cao Vit gibbons are suggested as potential tree species for ongoing habitat restoration.